1. Field Of The Invention
This invention relates to a door lock assembly, more particularly to a door lock assembly the backset of which is adjustable.
2. Description Of The Related Art
A conventional tubular door lock assembly usually includes a front plate which is adapted to be mounted on the edge of a door, a latch bolt which extends through the front plate and into a strike plate secured to a doorframe so as to close the door, and a spindle, which is operable to extract the latch bolt from the strike plate so as to open the door. The distance from the front plate to the center of the spindle is commonly referred to as a backset. Presently, there are two types of conventional tubular door lock assembly available in the market. One type of the conventional tubular door lock assembly used for a smaller door has a backset of 60 mm, while the other type of the conventional tubular door lock assembly used for a larger door has a backset of 70 mm. However, the backset of each type of the conventional tubular door lock assembly is fixed.